1. Field of the Invention
The present invention relates to an image processing technique, and more particularly, to a motion estimation method and related device.
2. Description of the Prior Art
Moving pictures include a series of static pictures. Usually, similar blocks will exist within two successive static pictures. Therefore, image data can be compressed by utilizing this property to reduce the amount of data to be transmitted.
When a prior art MPEG image data compression standard is employed to compress a current block in a current picture, a motion estimation operation is performed to search for a reference block that is most similar to the current block from a previous picture or a next picture. According to a result of the motion estimation operation, a motion vector of the current block is determined.
The above-mentioned motion estimation is typically realized by utilizing a block matching operation, for example, a full search block-matching scheme. A conventional block matching method performs a block matching operation within a search range corresponding to the current block. After completing the matching operation and obtaining a motion estimation of the current block, image data corresponding to the search range of a next block is loaded and a motion estimation operation continues similarly for the next block.
However, the prior art block matching method not only wastes many resources when in operation, but also requires considerable memory bandwidth for loading of the image data. As a result, the prior art method tends to negatively influence the normal operation of other devices and decreases the system efficiency for image processing.